| # DotStar strip driver for MicroPython |
| # |
| # The MIT License (MIT) |
| # |
| # Copyright (c) 2016 Damien P. George (original Neopixel object) |
| # Copyright (c) 2017 Ladyada |
| # Copyright (c) 2017 Scott Shawcroft for Adafruit Industries |
| # Copyright (c) 2019 Matt Trentini (porting back to MicroPython) |
| # |
| # Permission is hereby granted, free of charge, to any person obtaining a copy |
| # of this software and associated documentation files (the "Software"), to deal |
| # in the Software without restriction, including without limitation the rights |
| # to use, copy, modify, merge, publish, distribute, sublicense, and/or sell |
| # copies of the Software, and to permit persons to whom the Software is |
| # furnished to do so, subject to the following conditions: |
| # |
| # The above copyright notice and this permission notice shall be included in |
| # all copies or substantial portions of the Software. |
| # |
| # THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR |
| # IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, |
| # FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE |
| # AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER |
| # LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, |
| # OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN |
| # THE SOFTWARE. |
| |
| START_HEADER_SIZE = 4 |
| LED_START = 0b11100000 # Three "1" bits, followed by 5 brightness bits |
| |
| # Pixel color order constants |
| RGB = (0, 1, 2) |
| RBG = (0, 2, 1) |
| GRB = (1, 0, 2) |
| GBR = (1, 2, 0) |
| BRG = (2, 0, 1) |
| BGR = (2, 1, 0) |
| |
| |
| class DotStar: |
| """ |
| A sequence of dotstars. |
| |
| :param SPI spi: The SPI object to write output to. |
| :param int n: The number of dotstars in the chain |
| :param float brightness: Brightness of the pixels between 0.0 and 1.0 |
| :param bool auto_write: True if the dotstars should immediately change when |
| set. If False, `show` must be called explicitly. |
| :param tuple pixel_order: Set the pixel order on the strip - different |
| strips implement this differently. If you send red, and it looks blue |
| or green on the strip, modify this! It should be one of the values above |
| |
| |
| Example for TinyPICO: |
| |
| .. code-block:: python |
| |
| from dotstar import DotStar |
| from machine import Pin, SPI |
| |
| spi = SPI(sck=Pin(12), mosi=Pin(13), miso=Pin(18)) # Configure SPI - note: miso is unused |
| dotstar = DotStar(spi, 1) |
| dotstar[0] = (128, 0, 0) # Red |
| """ |
| |
| def __init__(self, spi, n, *, brightness=1.0, auto_write=True, pixel_order=BGR): |
| self._spi = spi |
| self._n = n |
| # Supply one extra clock cycle for each two pixels in the strip. |
| self.end_header_size = n // 16 |
| if n % 16 != 0: |
| self.end_header_size += 1 |
| self._buf = bytearray(n * 4 + START_HEADER_SIZE + self.end_header_size) |
| self.end_header_index = len(self._buf) - self.end_header_size |
| self.pixel_order = pixel_order |
| # Four empty bytes to start. |
| for i in range(START_HEADER_SIZE): |
| self._buf[i] = 0x00 |
| # Mark the beginnings of each pixel. |
| for i in range(START_HEADER_SIZE, self.end_header_index, 4): |
| self._buf[i] = 0xFF |
| # 0xff bytes at the end. |
| for i in range(self.end_header_index, len(self._buf)): |
| self._buf[i] = 0xFF |
| self._brightness = 1.0 |
| # Set auto_write to False temporarily so brightness setter does _not_ |
| # call show() while in __init__. |
| self.auto_write = False |
| self.brightness = brightness |
| self.auto_write = auto_write |
| |
| def deinit(self): |
| """Blank out the DotStars and release the resources.""" |
| self.auto_write = False |
| for i in range(START_HEADER_SIZE, self.end_header_index): |
| if i % 4 != 0: |
| self._buf[i] = 0 |
| self.show() |
| if self._spi: |
| self._spi.deinit() |
| |
| def __enter__(self): |
| return self |
| |
| def __exit__(self, exception_type, exception_value, traceback): |
| self.deinit() |
| |
| def __repr__(self): |
| return "[" + ", ".join([str(x) for x in self]) + "]" |
| |
| def _set_item(self, index, value): |
| """ |
| value can be one of three things: |
| a (r,g,b) list/tuple |
| a (r,g,b, brightness) list/tuple |
| a single, longer int that contains RGB values, like 0xFFFFFF |
| brightness, if specified should be a float 0-1 |
| |
| Set a pixel value. You can set per-pixel brightness here, if it's not passed it |
| will use the max value for pixel brightness value, which is a good default. |
| |
| Important notes about the per-pixel brightness - it's accomplished by |
| PWMing the entire output of the LED, and that PWM is at a much |
| slower clock than the rest of the LEDs. This can cause problems in |
| Persistence of Vision Applications |
| """ |
| |
| offset = index * 4 + START_HEADER_SIZE |
| rgb = value |
| if isinstance(value, int): |
| rgb = (value >> 16, (value >> 8) & 0xFF, value & 0xFF) |
| |
| if len(rgb) == 4: |
| brightness = value[3] |
| # Ignore value[3] below. |
| else: |
| brightness = 1 |
| |
| # LED startframe is three "1" bits, followed by 5 brightness bits |
| # then 8 bits for each of R, G, and B. The order of those 3 are configurable and |
| # vary based on hardware |
| # same as math.ceil(brightness * 31) & 0b00011111 |
| # Idea from https://www.codeproject.com/Tips/700780/Fast-floor-ceiling-functions |
| brightness_byte = 32 - int(32 - brightness * 31) & 0b00011111 |
| self._buf[offset] = brightness_byte | LED_START |
| self._buf[offset + 1] = rgb[self.pixel_order[0]] |
| self._buf[offset + 2] = rgb[self.pixel_order[1]] |
| self._buf[offset + 3] = rgb[self.pixel_order[2]] |
| |
| def __setitem__(self, index, val): |
| if isinstance(index, slice): |
| start, stop, step = index.indices(self._n) |
| length = stop - start |
| if step != 0: |
| # same as math.ceil(length / step) |
| # Idea from https://fizzbuzzer.com/implement-a-ceil-function/ |
| length = (length + step - 1) // step |
| if len(val) != length: |
| raise ValueError("Slice and input sequence size do not match.") |
| for val_i, in_i in enumerate(range(start, stop, step)): |
| self._set_item(in_i, val[val_i]) |
| else: |
| self._set_item(index, val) |
| |
| if self.auto_write: |
| self.show() |
| |
| def __getitem__(self, index): |
| if isinstance(index, slice): |
| out = [] |
| for in_i in range(*index.indices(self._n)): |
| out.append( |
| tuple(self._buf[in_i * 4 + (3 - i) + START_HEADER_SIZE] for i in range(3)) |
| ) |
| return out |
| if index < 0: |
| index += len(self) |
| if index >= self._n or index < 0: |
| raise IndexError |
| offset = index * 4 |
| return tuple(self._buf[offset + (3 - i) + START_HEADER_SIZE] for i in range(3)) |
| |
| def __len__(self): |
| return self._n |
| |
| @property |
| def brightness(self): |
| """Overall brightness of the pixel""" |
| return self._brightness |
| |
| @brightness.setter |
| def brightness(self, brightness): |
| self._brightness = min(max(brightness, 0.0), 1.0) |
| if self.auto_write: |
| self.show() |
| |
| def fill(self, color): |
| """Colors all pixels the given ***color***.""" |
| auto_write = self.auto_write |
| self.auto_write = False |
| for i in range(self._n): |
| self[i] = color |
| if auto_write: |
| self.show() |
| self.auto_write = auto_write |
| |
| def show(self): |
| """Shows the new colors on the pixels themselves if they haven't already |
| been autowritten. |
| |
| The colors may or may not be showing after this function returns because |
| it may be done asynchronously.""" |
| # Create a second output buffer if we need to compute brightness |
| buf = self._buf |
| if self.brightness < 1.0: |
| buf = bytearray(self._buf) |
| # Four empty bytes to start. |
| for i in range(START_HEADER_SIZE): |
| buf[i] = 0x00 |
| for i in range(START_HEADER_SIZE, self.end_header_index): |
| buf[i] = self._buf[i] if i % 4 == 0 else int(self._buf[i] * self._brightness) |
| # Four 0xff bytes at the end. |
| for i in range(self.end_header_index, len(buf)): |
| buf[i] = 0xFF |
| |
| if self._spi: |
| self._spi.write(buf) |